Author(s): Kattia Rubi Arnez Ferrel; Jonathan Nelson; Yasuyuki Shimizu
Linked Author(s): Yasuyuki Shimizu
Keywords: Ichilo River; Bank erosion; Meander migration; Neck cutoffs; Water level variation
Abstract: This study analyzes the planform evolution of a meandering river and its tributary, the Ichilo and the Sajta rivers, located in southern part of the Amazon basin in the city of Cochabamba, Bolivia by using Landsat imagery and the processing tool RivMAP to obtain meandering metrics. The analysis is performed along 150 kilometers of the Ichilo river from years 1988 to 2018. We observe the development of cutoffs, migration rates, and bank erosion and accretion processes. Furthermore, river morphology dynamics were mapped using images acquired with an unmanned aerial vehicle (UAV). The data obtained from the UAV was processed and orthophotomosaics were created. The results for this study helps us improve the understanding of the morphodynamics of the Ichilo River, showing that neck cutoffs are main controls in the planform configuration of the river. Our study suggest that ENSO events may have affected migration rates in Ichilo River in the year 2008. Furthermore, high water level variation and the groundwater levels may have an effect on bank erosion processes. Two possible scenarios where cutoffs are expected to occur were identified. These scenarios present further changes to the ever evolving landscape of the Ichilo river.
Year: 2020